Liquid expresser



.July 31, 1934. K R 1,968,638

LIQUID EXPRES SER Filed Sept. 19, 1931 3 SheetS Sheet 1 I50 11 me July 31, 1934. L, F, DU 1,968,638

LIQUID EXPRES SER Filed Sepia. 19. 1931 '3 Sheets-Sheet 2 Patented July 31, 1934 UNITED STATES PATENT OFFICE uqum nxrrmssea trustees Application September 19, 1931, Serial No. 563,839

My present invention is an elaboration of the inventions shown, described and claimed in my applications for Letters Patent on improvement in Liquid expressers, Serial No. 476,892, filed in the United States Patent Oflice August 21, 1930; Serial No. 484,418, filed in the United States Patent Ofllce September 25, 1930; Serial No.

522,981, filed in the United States Patent Oflice March 16, 1931; and Serial No. 524,619, filed in the United States Patent Oflice March 23, 1931. Liquid expressers of this character are employable in expressing liquid from laundry and from material which has been dry cleaned and for other purposes. The liquid expresser comprises a material chamber for receiving the material from which the liquid is to be expressed and a pressure chamber for receiving the fluid by which the liquid is expressed, there being a flexible wall between said chambers, which wall may be in the form of a bag and is hereinafter referred to as a bag.

It is the object of the present invention to provide a cover having coactive relation with the mouth end of the bag and novel means in connection with the bag at the outside of the cover and the tank for securing the cover in place and preventing leakage in the securing joint at the mouth of the tank; further, to provide aI novelarrangement of means whereby the flexible bag and the material therein after having been squeezed are again distended and the material in the bag agitated for loosening the material; further, to provide novel means for feeding liquid into the material chamber; and, further, to provide novel means for feeding the pressure fluid into the pressure chamber, and for the discharge of the fluid from the pressure chamber.

The invention will be further readily understood from the following description and claims, and from the drawings, in which latter:

Fig. 1 is a side elevation of my improved device in association with a stationary tub and a washing machine.

Fig. 2 is a plan view of the same, partly broken away, and showing the cover in various assumed positions in dotted lines for directing its spout in various directions.

Fig. 3 is a vertical axial section of the tank and reservoir of my improved device, showing the bag and material in expressed relation, and taken on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged detail of the closing means between the tank and its cover, taken on the'line 4--4 of Fi 2.

Fig. 5 is a cross-sectional detail view of the same, taken in the plane of the line 5- -5 01' Fig. 4. Fig. 6 is a plan view detail of the agitator, taken in the plane of the line 6-6 of Fig. 3. Fig. 'l is a detail view of the packing for the agitator stem, taken in section in the plane of the line 7-7 of Fig. 6. Fig. 8 is a detail showing a side elevation of a modification of the clamping means for the cover of my improved device.

Fig. 9 is a vertical section of the same, taken on the line 9-9 of Fig. 8.

Fig. 10 is a side elevation, partly in section, on a line similar to the line 33 of Fig. 2, and partly broken away, showing the pump and its conduits and portions of the reservoir.

Fig. 11 is a plan section showing the pump and its connections and taken on-the line 11--11 of Fig. 1; and.

Fig. 12 is a cross-section of the same, taken on the line 12-12 of Fig. 11. 7a

In the present exemplification of my invention there is atank 20 in which there is a bag, 21. The bag is arranged to receive the clothes or other material trom which the liquid is to be expressed, a body or batch of such material being shown at 22 in the bag. The bag forms a material chamber 23. (Fig. 3.)

The bag normally depends in the tank, the sides of the bag normally being close to the sides of the tank and the bottom of the bag being normally supported by the bottom of the tank. There is a fluid chamber 24 in the tank between the bag and the tank. The introduction of fluid pressure into the fluid chamber in the tank causes immediate spacing oi. the bag from the sides and bottom of the tank.

The bag is provided with a bead 25 about its mouth 26. The bag is exemplified of greater length than diameter. Adjacent to the mouth 28 of the tank, the tank is provided with an inner annular groove 29, shown formed by an outwardly bent armular bead 30 in the metal of the tank. (Figs. 3 and 4.) The bead 25 of the ba is shown located in this groove.

There is a cover 31 for the tank. The cover has an annular side wall 32 provided with an annular engaging face 33 to form an annular groove complemental to the annular groove 29 for receiving the head 25 or the bag.

The pressure fluid exerts pressure between the tank and the bag, causing flow of the fluid toward the joint between the mouth of the bag and the mouth of the tank, and there is also flow of the liquid from the material and a pressure of liquid. in the bag or material chamber which acts r on the joint between the mouth of the flexible bag and the cover. a

It is desirable that these joints be tight joints to prevent the flow of any fluid therethrough to the outside of the tank, while at the same time it is desirable to avoid the necessity of a great amount of clamping pressure upon the mouth of the bag. The tendency for the fluid or liquid to pass the joint at the mouth of the bag is especially evident at the beginning of the expressing operation where a solid bead is employed at the mouth of the bag.

I have provided means for avoiding such leakage in the form of a flexible flap at said joint, upon which the fiow of fluid or liquid acts for sealing the joint. The initial portion of the flow of fluid or liquid is arranged to act upon the flexible flap for sealing the joint as soon as the flow or the pressure begins.

For accomplishing this I have provided a flexible flap 41, at the inside of the bag arranged to coact with the coacting face 33. This flap and this face are shown annular with an annular space or groove 42 under the flap between the flap and the body of the bag. It is shown as part of the bead 25. When now the flow of fluid or pressure in the bag begins, it will be received in the annular groove 42 and thereby press the flexible flap toward its coacting face for sealing the joint at the mouth end of the bag. (Figs. 3 and 4.)

A flexible flap is also preferably provided at the outside of the mouth of the bag for sealing the joint between the mouth of the bag and the tank. Thus the bag 21 is provided with a flexible flap 43, under which there is a space or cavity shown as a groove 44. The flexible flap 43 is shown on the bead 25. These parts are preferably annular. At the beginning of the flow of fluid or of pressure of the fluid between the bag and the tank, flow or pressure is received in the groove 44 for forcing the flap 43 outwardly toward the wall of its groove for sealing the joint at the outside of the mouth of the bag.

Flow of fluid is thereby prevented past the joint between the mouth end of the bag and its holding means, so as to prevent leakage past the joint between the mouth of the tank and its cover and compel all of the fluid between the tank and the flexible bag to remain in the pressure chamber during the squeezing operation, and to cause the flow of liquid out of the material chamber through the cover and its discharging means.

This construction and arrangement permits a readily assembled connecting means between the cover and the tank to be employed.

The tank and cover may be formed of sheet metal. The tank is provided with an upwardly extending annular wall 46 located above the bead 30. The upwardly extending annular wall 46 is provided with an outwardly extending flange 47 which may take the form of a bead 48 and have an annular space 49 between it and the head 30. (Fig. 4.)

The upper end of the annular wall 32 of the cover is provided with an outwardly turned flange 51. Above this outwardly turned flange 51 there is an inwardly extending annular flat margin 52, the cover having an upward bulge 53 inside the margin. The outwardly extending annular flange 51 and the margin 52 are shown connected by a return bend 54, forming an inner annular slot 55.

The margin 56 of a perforated plate 57 is received in and held in this slot. This plate is provided with holes 58. It is shown spaced from the bulge by a discharge space 59, forming a discharge passage for the liquid expressed from the material and passing through the holes 58.

A discharge spout 61 is secured in the bulge of the cover and has a discharge passage 62 which connects with the discharge space 59, being suitably'flxed to the cover. The discharge spout is shown as a tube and also serves as a handle for manipulating the cover. (Figs. 1, 2 and 3.)

The cover is provided with hooks 64 at suitable points about its circumference, four being exemplified. These books comprise a base 65 suitably fixed to the margin 52 of the cover as by spot welding. Shanks 66 depend from these bases and at their lower ends have inwardly projecting hook ends 67 received under the head 48 at the upper end of the tank, through recesses 68 in said bead permitting passage of the hook ends when placing the cover on the tank. (Figs. 1, 2, 4 and 5.)

The respective ends of the hooks are provided with sloping ends 69, forming cam faces, for readily permitting passage of the ends of the hooks under the bead after passing the recesses 68, and firmly seating the cover on the mouth of the tank with the annular groove 33 thereof in proper position with relation to the annular groove 29 in the tank for positioning the bead at the mouth end of the bag. Teats 70 pressed outwardly from the wall 46 of the tank, form stops to limit rotation of the cover on the tank. These means form outer securing means between the cover and the tank.

In the modification shown in Figs. 8 and 9, the cover is secured to the tank by means of a lever '71 pivoted at 72 to a butt 73 flxed to the margin 52. The lever is provided with a roller 74 mounted on a pin 75, the ends of which are located in bearings 76 on inwardly extendingflanges 77 of the lever. The lever is outside the margin of the cover and the bead at the top of the tank. There are a suitable number of these lever fastening means arranged about the cover.

When the cover is removed from the tank, the levers may be swung upon the top of the cover. When the cover is to be placed on the tank, the annular side wall 32 thereof is placed in the tank, with the spout extending in desired direction, and the levers are swung outwardly and downwardly and the rollers 74 thereof forced under the head 48 of the tank, for drawing the cover firmly to its'seat on the tank, by the wedge-like action of the circumference of the roller and the bead. When the lever has been seated, the contact line between the roller and the bead is preferably inside of the right line intersecting the axes of the pivot of the lever and of the bead. This acts to lock the cover in place and to resist the pressure in the tank when extracting and expressing the liquid from the material.

The means provided for securing the cover to the tank are such that the cover is easily put in place in any desired angular position and definitely located with relation to the mouth end of the tank, the flange 51 on the cover resting upon the top of the tank for locating the groove at the lower end of the cover in proper relation to the groove in the mouth end of the tank, to receive and hug the bead at the mouth end of the bag, and form proper coacting resistance faces to movements of the flexible flaps on the respective sides of the mouth end of the bag.

The cover is arranged to be angularly positioned on the tank for directing the spout there- 1,'oes,ess

on in various directions, if it should be desired to employ the spout for discharging the expressed liquid forinstance into a power washing machine 78, a stationary tub 79, or other .receptacle, or drain, variously positioned about. the tank.

Fluid under pressure is arrangedto be received between the tank and the bag for surrounding the bag with a flexible pressure element in order to squeeze the bag and its contents and express the liquid from the material. This material is usually a saturated material, as clothes, or other material received from a power washing machine in the washing operation or material which has been dry cleaned or treated in other manner.

The pressure fluid is preferably water or other liquid which is substantially non-compressible but readily flowable in all directions, exerting its pressure in all directions, and is yieldable throughout to excess resistance for exerting uniform pressure upon all parts of the outside of the bag, and for exterting uniform pressure upon the material from the outside thereof to express the liquid therefrom.

The bag is preferably rendered impervious 'to the pressure medium and to the liquid in the bag. It may be made of soft pliable rubber similar to the rubber of an inner tube of an automobile tire and have the bead and its lips or flaps formed at its mouth. The pressure fluid may be water received from an ordinary water faucet through a suitable conduit leading into thepressure chamber, and the water may be discharged from the pressure chamber in suitable manner, for instance as explained in my copending applications aforesaid.

Means may also be provide for supplying a pressure fluid where a public water service is not available or such public water service has insufficient pressure for the purpose of expressing the liquid from the material in my improved device.

The power washing machine comprises a movable element, shown as an oscillating agitator 80, oscillated by suitable or usual gearing and eccentric and link mechanism in a casing 81 secured to the washing machine and operated by a motor 82, exemplified as an electric motor, although an explosive engine or other power supplying device may be used for the purpose. (Fig. 1.)

A reservoir 83 contains a body 84 of fluid, for instance water, forming a supply arranged to be passed through a pump for being fed into the pressure chamber 24 for pressing upon the material chamber and the material therein. (Figs. 1, 3 and 10.)

The reservoir is shown under the pressure chamber and is exemplified as having a side wall 85 forming an extension of the side wall 86 of the tank. A wall 87 separates the pressure chamber from the chamber of the reservoir. The pump is exemplified at 88 and is driven by the motor 82.

A relief valve 90 is located between these chambers so as to determine the maximum pressure in the pressure chamber. This relief. valve is shown comprising a tube 91 which has threaded connection 92 with a ferrule 93 secured in the dividing wall 87. It has a head 94 by means of which it may be rotated for withdrawing the tube for attention and for replacing the same. This tube or valve member has a valveseat 95 normally closed by a ball 96, the ball being backed by a spring 97 pressing the ball to its seat. An adjusting bolt 98 is threaded into the outer end of the tube and is arranged to adjust the spring for adjusting the pressure at which the ball will recede from its seat and thereby adjusting the maximum pressure permitted in the pressure chamber. The relief liquid passes through the hole 99 and side passages 100 in the tube into the reservoir.

The tank and reservoir are shown fixed to the power washing machine by brackets 103, 104, extending from plates 105, 106, suitably fixed to the power washing machine. These brackets may be extended as hoops or bands received about the side walls of the tank and reservoir and be secured thereto. (Figs. 1, 2, 10 and 11.)

A bracket 107 extends from the plate 106, the pump 88 being supported by and suitably fixed to said bracket.

The pump has a drive shaft 111 joumaled in bearings of its casing 114. It has a pulley 115 fixed thereto. A pulley 116 is loose on one of the operating shafts 117 driven by the motor 82, and is held axially thereon between a bearing 118 off said shaft and a flange 119 on a bushing 120 fixed in the bearing 118. (Figs. 1, 10, 11 and 12.)

A clutch collar 121 is movable endwise on said shaft and has spline key and groove connection 122 therewith. There is aclutch 123 between said clutch collar and .the pulley 116, the clutch faces thereof being shown as toothed clutch faces, although it is obvious that any other form of clutch may be employed. A flexible driving member shown as a belt 113 is received about said pulleys. (Fig. 12.)

A rock shaft 125 is journaled in a lug 126 of a plate 12? fixed hi the framing 12s of the washing machine and a bearing 124 at the outer edge of said framing and has a shifting handle 129 flxed thereto. This rock shaft has an arm 130 fixed thereto, a link 131 being articulated therewith at 132. The link has an articulation 133 with a fork 134 received in an annular groove 135 in the clutch collar. The fork is longi tudinally slidable on a rod 136 fixed in bearings 137 of the plate 127. (Figs. 1, 2, 11 and 12.)

The handle 129 may be shifted for moving the clutch face on the clutch collar into engagement with the clutch face on the pulley 116 for operating the pump, or it may be shifted for moving the clutch collar out of engagement with the pulley 116 when the pump is not being used. The arm and link may be placed in substantial line with each other when the clutch is engaged for locking the clutch in engaged relation. Stops 138, 139, on the washing machine may limit the movements of the handle 129. (Fig. 1.)

A conduit comprising conduit sections 141, 142, connects a port 143 in the lower end of the reservoir with the intake port 144 of the pump. (Fig. 10.) A conduit 145 connects with the outlet port 146 of the pump and connects with the port 147 for the pressure chamber 24. This port is shown located in the side wall of the tank. A conduit 148 connects with a valve 149 and with the conduit 145. The valve has ports 151,152, 153, and a valve plug 154 having a passage 155. A handle 150 is on the plug. (Fig. 1.) This valve is shown as a two-way valve. The

reservoir is provided with a port 158 for con-' J necting the space in the reservoir with the atmosphere, for preventing pressure and vacuum in the reservoir. This port may have a tube 157 communicating therewith, which may be of glass and form a sight tube for the level of liquid in the reservoir, and may also serve as a filler-tubefor the reservoir. (Figs. 1, 3 and 10.)

When the passage 155 connects the conduit sections 142, 141, and the pump is operated, liquid in the reservoir will be drawn from the reservoir through the valve past the ports 151, 152, through the pump and through the conduit 145 and the port 147 into the pressure chamber 24, the port 153 of the valve being closed by its plug. Suitable stops for the plug may be provided. Liquid from the reservoir will be pumped into the pressure chamber until the maximum pressure in the pressure chamber, determined by the setting of the reliefvalve 90, for example forty or fifty pounds per square inch, is reached, after which the relief valve opens and excess pressure in the pressure chamber is avoided by flow of liquid from the pressure chamber through the relief valve back into the reservoir.

When the pressure has been sustained in the pressure chamber for the desired length of time, the clutch 123 is released and the valve plug 154 is rotated by its handle 150 for closing the port 152 and opening the port 153, whereupon the liquid in the pressure chamber 24 flows through the port 147, the conduits 145, 148 and 142, the ports 153, 151, of the valve 149, and the port 143 of the reservoir for passage of the liquid back from the pressure chamber to the reservoir.

It may be-desirable to introduce rinsing water, bluing water or other treating liquid into the material chamber while the cover is in place on the tank, for instance for rinsing the material or bluing the material. It is desirable when so treating the material that the material shall be quickly loosened so that the fresh liquid may be readily received and soaked into all parts of the material.

For accomplishing this an agitator 161 is provided in the material chamber operable from outside the material chamber. This agitator may comprise a head 162, for instance of wood or rubber and suitably shaped. It is shown formed with projections 163, and provided with holes 164, the head being fixed to a. stem 165. The stem is automatically movable axially in the cover in response to pressure in axial direction on the material in the expressing operation. (Figs. 1, 2, 3, 6 and 7.)

There is a water tight joint between the stem and the cover. The stern may operate in a tube 166 fixed to the crown portions of the cover and the perforate plate 57, forming water tight connections therewith. This tube is provided with an internal flange 167 and has a follower plug 168 threaded therein at 169. Packing 170 is located between the flange and the inner end of the follower plug, the flange and follower plug being for instance provided with tapering faces 171, 172, coacting with the packing to squeeze the packing toward the stem and form a water seal therewith while permitting the stem to move axially and rotatively in the packing.

In order to feed fluid into the material chamher when the cover is closed, the stem 165 may be a hollow tube provided at its top with a valve 173 having a nipple 174 to which a hose 175 may be firmly secured, the hose leading to a faucet 176, or other suitable source of rinsing water, bluing 'water, or qualifying agent, which may be fed into the material chamber through the hose, the nipple, the valve and the stem.

After the material has been squeezed for expressing the liquid therein, the stem may be pushed downwardly for aiding the downward movement of the bag and material, and the stem may also be rotated, similar movements being thereby imparted tothe head, which is moved axially and rotatively thereby while the conditioning liquid is being fed into the material chamber for agitating the material and soaking the same.

When the material has been properly agitated and soaked the stem is preferably raised so as to place the agitator head next to the cover, the

' pressure fluid being then introduced into the pressure compartment for again expressing the freshly introduced liquid from the material. The head is preferablyprovided with knobs 177 arranged to contact the perforated plate 57 so as to form passageways 178 between the head and the perforated plate, and the knobs are preferably out of register with the holes 58 in the plate 57 for avoiding obstruction of the holes in the perforated plate. The holes 164 communicate with the passageways 178. (Figs. 3 and 6.)

In operation the cover is released from the tank and the saturated material is placed in the bag. The cover is then replaced and fastened to the tank in such position that the discharge spout thereof extends in the desired direction about the axis of the tank for discharging the expressed liquid. The securing means between the cover and the tank permit this to be readily done and provide easy manipulation for the parts and for connecting the cover with the tank in proper relation for securing the bag in place and resisting pressures at both sides of the bag.

The clutch 123 is then connected and the valve 149 manipulated for causing flow of the liquid from the reservoir to the pressure chamber and building up pressure in the pressure chamber to the desired limit, excess pressure being relieved through the relief valve 90.

This pressure acts with side pressure upon the elongated sides of the bag and with end pressure upon the end of the bag. This action of the pressing fluid upon the bag and the material therein is in simulation of the squeezing of saturated material between the human hands, but with a cushioning fluid, and is a squeezing action upon the material without relative distortion between the portions of the material or twisting of the material.

The action of the compressing fluid upon the bag is to contract the bag and thereby close any punctures, holes or leaks theremay be in the bag, and to avoid the formation of any such holes, punctures or leaks during the pressing operation. Any hard objects among the material, such as buttons, buckles or the like, are cushioned against the material and if they should contact the bag, there is no danger of puncturing the bag because the squeezing action is to compress the constituent parts of the bag against each other, rather than to expand the same, and to crowd the constituent parts of the bag about any such hard object for cushioning the hard object, as distinguished from a stretching of the portion of the bag about a hard object.

These actions are more fully described and the relations of parts accomplishing the same more broadly claimed in my aforesaid copending applications hereinbefore mentioned.

After the pressure has been maintained for the desired period, the clutch 123 is released for stopping the pump and the valve 149 manipulated for closing the port 152 and opening the port 154, permitting the liquid in the pressure chamber to return to the reservoir.

'I'he return of this liquid may be expedited by opening ,the faucet 176 if it is desired to introduce rinsing water into the material chamber, or 'if it is desired to introduce bluing water or other qualifying material into the material chamber, for instance as set forth in my aforesaid copending application Serial No. 484,418. It may also be expedited by manipulation of the agitator for moving the bag and material downwardly and for loosening the material in the bag.

water or other agency intothe material chamber, or the use of theagitator and the loosening and re-saturating of the material, the liquid in the material may be again expressed by again operating the pump and. manipulating the valve 149 for causing flow of the liquid from the reservoir into the pressure chamber.

I do not herein claim the general arrangement of material chamber, pressure chamber and flexible wall or bag between said chambers, nor the relation and forms of the same; nor the relation of an elongated bag and an elongated tank; nor an impervious flexible bag having greater side area throughout its length than end area at the movable end thereof; nor broadly means nor method for expressing the liquid or rinsing the material; nor broadly shifting the spout into various radial positions; nor broadly providing an expansible member at the mouth of said bag; nor connecting means. at the outsides of the margins of the tank and cover, herein shown and described, having shown, described and claimed the same in my aforesaid copending applications Serial No. 476,892; Serial No. 484,418; and Serial No. 522,981 and Serial No. 524,619; nor do I herein claim a flexible flap or flaps at the mouth of the bag, nor the association of the cover and mouth of the tank therewith herein shown and described, having shown, described and claimed the same in my aforesaid copending application Serial No. 524,619.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is:

1. In apparatus of the character described, the combination of a tank, a closure therefor, a flexible imperforate bag in said tank having a bead at its mouth, said tank having an inwardly presented annular groove in which said bead is received for suspendingly supporting the bag within the tank and an outwardly extending flange above said groove forming a rim for the open end of the tank, said closure having a rim for engaging with the rim of the tank and with the bead of the bag for confining the bead within said annular groove of the tank for a fluid tight connection of said parts.

2. In apparatus of the character described, the combination of atank, a closure therefor, a flexible imperforate bag in said tank arranged for receiving liquid-containingmaterial, means for admitting pressure fluid between said tank and said bag for compressing said bag and the material therein, means for escape of expressed liquid from said bag, and an agitator for the contents of said bag movable in the bag and having a stem slidably engaged through said closure for distending the bag when compressed.

3. In apparatus of the character described, the combination of a tank, a closure therefor, a flexible imperforate bag in said tank, means for admitting pressure fluid between said tank and said flexible bag, means for escape of expressed liquid from said bag,,'said bag arranged .for re-- ceiving liquid-containing material, and an agitator for the contents of said bag slidably depend-'- ing from said closure into the bag.

4. In apparatus of the character described, the combination of a tank, a closure therefor, a flexible imperforate bag in said tank, said bag forming a material compartment, a pressure conipartment between said tank'and said bag for squeezing said bag and the material therein, means After the introduction of the rinsing or 'bluingfor escape of liquid from the material; an agitator on said closure and depending into said bag for agitating the material in said flexible bag, liquid supply means for said material compartment, and fluid supply means for said pressure compartment.

5. In an apparatus of the character described, a cylindrical container, a fluid tight collapsible bag suspended within said container with the rim at the open end of the bag in sealing connection with the container, the bag and its contents compressed for expressing liquid from the contents by a pressure fluid admitted into and confined between the container and the exterior of the bag, a ported closure for the open end of the bag removably supported on said container, and a bag contents agitating plunger movably supported upon said closure for reciprocating and depending the plunger within the bag.

6. In an apparatus of the character described, a cylindrical container, a fluid tight collapsible bag having a rim connection with the container at the open end of the bag for suspending the bag withinsaid container, the bag compressible for expressing liquid from the contents thereof, a ported closure for the open end of the bag removably supported on said container, 9, liquid dispensing and bag contents agitating plunger of a tubular stem movably supported upon said closure for extending into the bag, and a forked sprayer head upon the end of the stem within the bag.

'7. In an apparatus of the character described, a cylindrical container, a fluid tight collapsible bag having at its open end a rim connection with the container for suspending the bag within said container, the bag compressible for expressing liquid from the contents thereof, a ported closure for the open end of the bag removably supported on said container, and a liquid dispensing and bag contents agitating plunger movably supported upon said closure for reciprocating and depending the plunger within the bag.

8. In an apparatus of the character described, a tank having a flexible diaphragm therein dividing the same into an upper expressing chamber and a lower fluid pressure chamber, a reservoir below said fluid pressure chamber and separated therefrom by an imperforate wall, a pump for forcing fluid from the reservoir and into the pressure chamber, means for controlling the pressure in said last chamber, comprising a relief valve in said wall opening into the reservoir and means for enabling the fluid to escape from said expressing chamber.

9. In an apparatus of the character described, a tank having a flexible diaphragm therein dividing the same into an upper expressing chamber and a lower fluid pressure chamber, a reservoir below said fluid pressure chamber and separated therefrom by an imperforate wall, a pump for forcing fluid from the reservoir and into the pressure chamber, means for controlling the pressure in said last chamber, comprising a relief valve in said wall opening into the reservoir and means for enabling the fluid to escape from said expressing chamber, and agitating mechanism in the expressing chamber. i

10. In an apparatus of the character described, a tank having an expressing chamber, a

6 fluid pressure chamber, the expressing chamber separated by a flexible partition from said ,fluid pressure chamber, means for escape of fluid from said expressing chamber, a reservoir for said fluid pressure chamber andseparated therefrom by an 

